The present invention relates to a device for a temporary attachment of a container, preferably of an elastic container, in a filling position on a feed connection piece. The device is of the type which includes expanding members movable against inner wall of the container, thus affixing the same in filling position.
In charging or filling loose goods or liquids moving through a feed connection piece, into elastic or flexible containers such as for example bags or sacks, it is necessary to hold the container at least for the time interval of feeding in a fixed open position below the feed connection piece. In addition, in order to prevent the discharge of granular goods from the connection piece past the container it is advantageous when the connection piece projects into the container and the latter is directly attached to the connection piece whereby a tight seal against ambient environment is usually desired.
From the German Publication DE-GM No. 77 27 248 a device is known in which open part of sacks to be filled is drawn over two holding yokes of suitable shape whereupon the latter are pressed apart from the other by a spring force to exert pressure against the inner surface of the sack and simultaneously fix the same in its open filling position. The disadvantage of this prior art device is its relative complexity requiring an expensive system of pedals, deviation levers, ropes and springs while the problem of sealing the gap between the feed connection piece and the sack is not solved. In all prior art devices of this kind using mechanical expansion members in the form of holding yokes, levers and the like, the path and force of movement of the expansion members acting on the inner wall of the container can be readily realized. However the sealing action between the container and the feed connection piece has always presented problems in practice.
Other known devices of this kind which consider the sealing problem for example by using inflatable sealing organs such as rubber rings inflatable against the inner walls of containers to be charged, are more advantageous. Nevertheless, even in this case disadvantages are present because of generally smaller path of travel of the expansion organs in comparison with before described mechanical expansion systems, or oversized and large volume inflatable expansion organs must be used. Moreover, pneumatic holding systems of this kind do not act against a limit stop but only engage against the material of the container being filled. Consequently, in the event of pressure fluctuations the flexible container is prone to be over expanded or alternatively is insufficiently held in a fixed position.